The present disclosure relates in general to semiconductor device structures and their fabrication. More specifically, the present disclosure relates to the fabrication of a fin-type field effect transistor (FinFET) having a gate region wrapped around moderately doped source and drain regions.
Phase change memory (PCM) is a non-volatile solid-state memory technology built around the large electrical contrast between the highly-resistive amorphous and highly-conductive crystalline states in so-called phase change materials. For high density PCM technologies, it is necessary to use nanometer scaled access transistor configurations having relatively short channels. A FinFET device can be scaled to nanometer dimensions and provides a short channel appropriate for use as the access transistors for high density PCM cells. Because a relatively shorter channel is more susceptible to leakage currents, moderate doping of the FinFET source and drain regions may be provided to suppress leakage current of unselected FinFET cells during read and programming conditions. However, moderate doping of the FinFET source and drain regions results in high parasitic resistance in the source and drain regions, which degrades access transistor drive current.